After a little research I found the tool diagram blow up on Sewell's part site. Looks like none of the GX460's came with a full set for the plastic inlay. In case your curious, they are listed under engine and they are the first schematic that pulls up under that subheading.

Additionally after looking at the GX470's it seems, all the tools were included including the spark plug tool were included.

Since the spark plugs are different for the 460 & 470, perhaps they use a different wrench size?